feat: add HuggingFace mirror support for VM providers (#278)

Add support for HuggingFace mirror (hf-mirror.com) to improve download
speeds in regions where huggingface.co access is slow.

- Support HF_ENDPOINT environment variable detection
- Automatically switch to hf-mirror.com when HF_ENDPOINT is set
- Apply to Docker, VMware, and VirtualBox providers
- Maintain backward compatibility with default huggingface.co URLs

Users can now set HF_ENDPOINT=https://hf-mirror.com to use the mirror.

desktop_env/providers/virtualbox/manager.py

@@ -57,6 +57,12 @@ def _install_vm(vm_name, vms_dir, downloaded_file_name, original_vm_name="Ubuntu
         else:
             raise Exception("Unsupported platform or architecture.")
 
+        # Check for HF_ENDPOINT environment variable and replace domain if set to hf-mirror.com
+        hf_endpoint = os.environ.get('HF_ENDPOINT')
+        if hf_endpoint and 'hf-mirror.com' in hf_endpoint:
+            url = url.replace('huggingface.co', 'hf-mirror.com')
+            logger.info(f"Using HF mirror: {url}")
+
         # Download the virtual machine image
         logger.info("Downloading the virtual machine image...")
         downloaded_size = 0